Struct Hashmap中的多个可变借用

use std::collections::HashMap;

let mut map: HashMap<String, i32> = HashMap::new();

use std::collections::HashMap;

fn main() {
    let mut map = HashMap::new();
    map.insert("key1", 1);
    map.insert("key2", 2);

    let mut value1 = map.get_mut("key1").unwrap();
    let mut value2 = map.get_mut("key2").unwrap();

    *value1 += 1;
    *value2 += 1;
}

use std::collections::HashMap;
use std::sync::{Arc, Mutex};
use std::thread;

fn main() {
    let map = Arc::new(Mutex::new(HashMap::new()));
    let map_clone = Arc::clone(&map);

    let handle = thread::spawn(move || {
        let mut map = map_clone.lock().unwrap();
        map.insert("key1", 1);
    });

    handle.join().unwrap();

    let mut map = map.lock().unwrap();
    map.insert("key2", 2);
}

use std::collections::HashMap;
use std::sync::{Arc, RwLock};
use std::thread;

fn main() {
    let map = Arc::new(RwLock::new(HashMap::new()));
    let map_clone = Arc::clone(&map);

    let handle = thread::spawn(move || {
        let mut map = map_clone.write().unwrap();
        map.insert("key1", 1);
    });

    handle.join().unwrap();

    let map = map.read().unwrap();
    println!("{:?}", *map);
}